Abstract
A marine dinoflagellate Pyrodinium bahamense has two varieties: var. bahamense (PBB) and var. compressum (PBC). Using cultures of both PBB and PBC, we examined their physiological characteristics. PBB was from Puerto Rico and PBC from the Philippines. Their growth was monitored using the in vivo fluorescence method for one or two days. PBB grew under intense light exceeding 125 μEm-2s-1, broader ranges in temperature (20-33°C) and salinity (20-50‰). The highest growth rate 0.38 divisions day-1 was recoded at 28°C and salinities of 25-36. For PBC, the, minimum light intensity for growth was 75 μEm-2s-1. The temperature and salinity tolerance ranges were 25-30°C and 25-50‰, respectively, with the highest growth rate 0.2 divisions day-1 at 28°C and 32.5-50‰. These results show clear differences in the growth-physiological characteristics between the two varieties This is the first report that compared the growth-physiological characteristics between two varieties of Pyrodinium bahamense.
